Tuesday, 13 May 2014

Those who suffer from an accident, a
stroke or a debilitating injury typically have to face an extremely long and
difficult ordeal having to make a recovery or get back to any resemblance of
normal lifestyle. Going through physical therapy can be a long and hard journey
and there is often no guarantee of that person making a full recovery. While
there are such things as robotic exoskeletons that can provide support and help
for people, they usually come with very high cost and generally need to be
plugged into an electrical outlet. However students from the University of Pennsylvania have built what they
say is a portable and affordable robotic arm exoskeleton.

[Image
Courtesy of Marius Bugge]

The students are a team of
mechanical engineers and over two semesters, many long hard working nights and
weekends, Elizabeth Beattie, Nicholas McGill, Nick Parrotta, and Nikolay
Vladimirov came up with what they have called the Titan Arm. The
invention is an exoskeleton that is not only lightweight and
efficient but also very powerful. The electronic muscle would be able to
offer resistance when undertaking therapeutic exercises and allows the person
wearing it to be able to pick up and additional 40 pounds in weight without
breaking into a sweat.

Thanks to the Titan Arm having been made
a lot slimmer than other robotic arms, it is easier for patients to
use. To do this the team placed the actuator in a backpack instead of
placing it into the actual limb of the robotic arm. Load bearing parts of
the exoskeleton were milled from aluminium so as to keep the weight down
as much as possible along with the amount of power used. The electronics lead,
McGill, came up with a software and sensor package that can track the arm
movements and the relay the data wirelessly. This means that the Titan Arm
could be used by the patient at home while their therapist could monitor
exercises remotely.

[Image Courtesy of Marius Bugge]

There are many potential uses for
the Titan Arm and the team have already had encouragement from a snowboarder
that was injured and many victims of a stroke, all of which have gone towards
pushing the goal of a finished product from the $2,000 prototype.
The team are now looking into designing a new prototype which is more
refined. One of the designers said that they were looking into 3D printing so that they would be able to
customise parts, much the same way as someone has a suit tailored to fit
them.

Theexoskeleton arm is powered by a
Lithium-polymer battery that will offer the wearer a full day’s use. While
the muscle comes courtesy of an electric motor that is stored in the backpack
and which winds steel cables so that pulleys are rotated and make the arm move.
A support system was also designed that would distribute the weight safely
across a back plate, elbow straps and hip belt. The clever part of the robotic
arm comes from software that can read the magnetic sensors positions within the
steel joints and then tell the arm to move; the operator the arm is able to
control this via a handheld device.